If the certificates relation has been set from a consuming charm for
certificates, but the provider hasn't supplied a certificate, and the
request is in the 'legacy' form, then the get_request_for_local_unit()
function in cert_utils fails on accessing the (non-existant) 'ca'
parameter in the databag. This patch ensures that if the 'ca' key is
missing that the processing moves on to the next relation.
If the certificates relation has been set from a consuming charm for certificates, but the provider hasn't supplied a certificate, and the request is in the 'legacy' form, then the get_request_for_local_unit() function in cert_utils fails on accessing the (non-existant) 'ca' parameter in the databag. This patch ensures that if the 'ca' key is missing that the processing moves on to the next relation.
Closes LP#2028683